v1.12.0: per-page admin permissions + SO line editing

"Admin permissions and SO editing" release. Web-admin USERs gain per-page permission grants and a new so-full-edit override; the admin SO surface gains line-level CRUD with allocation-release, shipment-state backfill fields, a company-local Shipped Date, and a denormalised source_system tag.

Mobile. Zero mobile/ diffs on this release; no new APK build for v1.12.0.

Added

• Per-page permission grants for web-admin USERs (#356): user_page_permissions (migration 061), /auth/me allowed_pages, the @require_admin_or_page_permission decorator across every admin endpoint, sidebar filtering, a permission grid on the Users form, and one clean Permissions Error popup (background fetches are silenced via silentPermissionDenied).
• Admin SO editing expansion (#357): header edits at any status (ADMIN), shipment-state backfill fields on PUT, api version in the topbar, and a company-local Shipped Date driven by the new SENTRY_COMPANY_TIMEZONE env (IANA zone, default UTC) -- manually-picked dates anchor at noon company-local so they read back as the same calendar date across DST.
• SO line CRUD + so-full-edit override + source_system (#358): line add/update/remove with an allocation-release pass, the so-full-edit override in a separate Overrides grid group, sales_orders.source_system (migration 062, FK to the inbound allowlist, backfilled), per-field edit audit rows, and a sectioned edit modal with an editable line table.

Migrations

• 061 (#356) -- user_page_permissions table.
• 062 (#358) -- sales_orders.source_system + allowlist FK + backfill.

See CHANGELOG.md for the full notes.